[INTERNAL] sap/ui/core/Configuration: Improve collecting changes
[INTERNAL] sap/ui/core/Configuration: Improve collecting changes

- Delete mChanges and mChanges.__count together instead of deleting
  count before fireLocalizationChange and the mChanges itself
  afterwards
- Fixes an issue for the case, that a second fireLocalizationChange is
  triggered for the same changed property as the fireLocalizationChange
  before

Change-Id: I5729bf54895564b42f3a2517241a4f8d4b32b66a
JIRA: CPOUI5FRAMEWORK-396

SAP/openui5,SAP/openui5,SAP/openui5,SAP/openui5